This invention is directed to a system and method for managing memory for color transforms, particularly as applied to digital imaging devices. In particular, the system and method. of the present invention reduce the amount of memory required for transfer functions, under color removal, and black generation. The system and method of the present invention reduce the memory usage for color transforms by using a lookup table having an associated reference counter and a function cache.
Device profiles are used to translate color data created on one device into another device's native color space. Each device profile enables a color management system with information necessary to convert or transform color data between a native device color space and a device independent color space. A color space is typically a particular model of colors, represented by a tri-dimensional map. There are three broad classes of devices, which are input devices, display devices, and output devices. For each device class, a series of base algorithm models describe a transformation between color spaces.
A typical color transformation requires four lookup tables for transfer functions and two lookup tables for under color removal and black generation. Each lookup table requires at least 256 bytes of memory for 8-bit. Therefore, a color transform requires at least 1.5 kilobytes of memory for the lookup tables required for the transfer functions, under color removal, and black generation. If a document processing job requires four thousand color transformations, six megabytes of memory for the transfer functions, under color removal, and black generation will be required. As such, multiple jobs, each having thousands of color transformations, will likely require all of the system memory and may eventually cause the system to crash. There is a need for a system and method to reduce the amount of memory required for transfer functions, under color removal, and black generation.
The subject invention overcomes the above-noted problems and provides a system and method for managing memory for color transforms.